1// cref.cc -- cross reference for gold
2
3// Copyright (C) 2008-2017 Free Software Foundation, Inc.
4// Written by Ian Lance Taylor <iant@google.com>.
5
6// This file is part of gold.
7
8// This program is free software; you can redistribute it and/or modify
9// it under the terms of the GNU General Public License as published by
10// the Free Software Foundation; either version 3 of the License, or
11// (at your option) any later version.
12
13// This program is distributed in the hope that it will be useful,
14// but WITHOUT ANY WARRANTY; without even the implied warranty of
15// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16// GNU General Public License for more details.
17
18// You should have received a copy of the GNU General Public License
19// along with this program; if not, write to the Free Software
20// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
21// MA 02110-1301, USA.
22
23#include "gold.h"
24
25#include <cerrno>
26#include <cstdio>
27#include <cstring>
28#include <map>
29#include <string>
30#include <vector>
31
32#include "object.h"
33#include "archive.h"
34#include "symtab.h"
35#include "cref.h"
36
37namespace gold
38{
39
40// Class Cref_inputs.  This is used to hold the list of input files
41// for cross referencing.
42
43class Cref_inputs
44{
45 public:
46  Cref_inputs()
47    : objects_(), archives_(), current_(&this->objects_)
48  { }
49
50  // Add an input object file.
51  void
52  add_object(Object* object);
53
54  // Start adding an archive.  We support nested archives for future
55  // flexibility.
56  void
57  add_archive_start(Archive*);
58
59  // Finish adding an archive.
60  void
61  add_archive_stop(Archive*);
62
63  // Report symbol counts.
64  void
65  print_symbol_counts(const Symbol_table*, FILE*) const;
66
67  // Print a cross reference table.
68  void
69  print_cref(const Symbol_table*, FILE*) const;
70
71 private:
72  // A list of input objects.
73  typedef std::vector<Object*> Objects;
74
75  // Information we record for an archive.
76  struct Archive_info
77  {
78    // Archive name.
79    std::string name;
80    // List of objects included from the archive.
81    Objects* objects;
82    // Number of archive members.
83    size_t member_count;
84  };
85
86  // A mapping from the name of an archive to the list of objects in
87  // that archive.
88  typedef std::map<std::string, Archive_info> Archives;
89
90  // For --cref, we build a cross reference table which maps from
91  // symbols to lists of objects.  The symbols are sorted
92  // alphabetically.
93
94  class Cref_table_compare
95  {
96  public:
97    bool
98    operator()(const Symbol*, const Symbol*) const;
99  };
100
101  typedef std::map<const Symbol*, Objects*, Cref_table_compare> Cref_table;
102
103  // Report symbol counts for a list of Objects.
104  void
105  print_objects_symbol_counts(const Symbol_table*, FILE*, const Objects*) const;
106
107  // Report symbol counts for an object.
108  void
109  print_object_symbol_counts(const Symbol_table*, FILE*, const Object*) const;
110
111  // Gather cross reference information.
112  void
113  gather_cref(const Objects*, Cref_table*) const;
114
115  // List of input objects.
116  Objects objects_;
117  // List of input archives.  This is a mapping from the archive file
118  // name to the list of objects.
119  Archives archives_;
120  // The list to which we are currently adding objects.
121  Objects* current_;
122};
123
124// Add an object.
125
126void
127Cref_inputs::add_object(Object* object)
128{
129  this->current_->push_back(object);
130}
131
132// Start adding an archive.
133
134void
135Cref_inputs::add_archive_start(Archive* archive)
136{
137  gold_assert(this->current_ == &this->objects_);
138  if (this->archives_.find(archive->name()) == this->archives_.end())
139    {
140      Archive_info* pai = &this->archives_[archive->name()];
141      pai->name = archive->filename();
142      pai->objects = new Objects();
143      pai->member_count = archive->count_members();
144    }
145  this->current_ = this->archives_[archive->name()].objects;
146}
147
148// Stop adding an archive.
149
150void
151Cref_inputs::add_archive_stop(Archive*)
152{
153  gold_assert(this->current_ != &this->objects_);
154  this->current_ = &this->objects_;
155}
156
157// Report symbol counts for an object.
158
159void
160Cref_inputs::print_object_symbol_counts(const Symbol_table* symtab,
161					FILE* f,
162					const Object* object) const
163{
164  size_t defined, used;
165  object->get_global_symbol_counts(symtab, &defined, &used);
166  fprintf(f, "symbols %s %zu %zu\n", object->name().c_str(), defined, used);
167}
168
169// Report symbol counts for a list of inputs.
170
171void
172Cref_inputs::print_objects_symbol_counts(const Symbol_table* symtab,
173					 FILE* f,
174					 const Objects* objects) const
175{
176  for (Objects::const_iterator p = objects->begin();
177       p != objects->end();
178       ++p)
179    this->print_object_symbol_counts(symtab, f, *p);
180}
181
182// Print symbol counts.  This implements --print-symbol-counts.  This
183// is intended to be easily read by a program.  This outputs a series
184// of lines.  There are two different types of lines.
185
186// The first is "symbols FILENAME DEFINED USED".  FILENAME is the name
187// of an object file included in the link; for an archive, this will
188// be ARCHIVEFILENAME(MEMBERNAME).  DEFINED is the number of symbols
189// which the object file defines.  USED is the number of symbols which
190// are used in the final output; this is the number of symbols which
191// appear in the final output table as having been defined by this
192// object.  These numbers will be different when weak symbols are
193// used, and they will be different for dynamic objects.
194
195// The second is "archives FILENAME MEMBERS USED".  FILENAME is the
196// name of an archive file included in the link.  MEMBERS is the
197// number of members of the archive.  USED is the number of archive
198// members included in the link.
199
200void
201Cref_inputs::print_symbol_counts(const Symbol_table* symtab, FILE* f) const
202{
203  this->print_objects_symbol_counts(symtab, f, &this->objects_);
204  for (Archives::const_iterator p = this->archives_.begin();
205       p != this->archives_.end();
206       ++p)
207    {
208      fprintf(f, "archive %s %zu %zu\n", p->second.name.c_str(),
209	     p->second.member_count, p->second.objects->size());
210      this->print_objects_symbol_counts(symtab, f, p->second.objects);
211    }
212}
213
214// Sort symbols for the cross reference table.
215
216bool
217Cref_inputs::Cref_table_compare::operator()(const Symbol* s1,
218					    const Symbol* s2) const
219{
220  int i = strcmp(s1->name(), s2->name());
221  if (i != 0)
222    return i < 0;
223
224  if (s1->version() == NULL)
225    {
226      if (s2->version() != NULL)
227	return true;
228    }
229  else if (s2->version() == NULL)
230    return false;
231  else
232    {
233      i = strcmp(s1->version(), s2->version());
234      if (i != 0)
235	return i < 0;
236    }
237
238  // We should never have two different symbols with the same name and
239  // version.
240  if (s1 == s2)
241    return false;
242  gold_unreachable();
243}
244
245// Gather cross reference information from a list of inputs.
246
247void
248Cref_inputs::gather_cref(const Objects* objects, Cref_table* table) const
249{
250  for (Objects::const_iterator po = objects->begin();
251       po != objects->end();
252       ++po)
253    {
254      const Object::Symbols* symbols = (*po)->get_global_symbols();
255      if (symbols == NULL)
256	continue;
257      for (Object::Symbols::const_iterator ps = symbols->begin();
258	   ps != symbols->end();
259	   ++ps)
260	{
261	  const Symbol* sym = *ps;
262	  if (sym == NULL)
263	    continue;
264	  Objects* const onull = NULL;
265	  std::pair<Cref_table::iterator, bool> ins =
266	    table->insert(std::make_pair(sym, onull));
267	  Cref_table::iterator pc = ins.first;
268	  if (ins.second)
269	    pc->second = new Objects();
270	  if (sym->source() == Symbol::FROM_OBJECT
271	      && sym->object() == *po
272	      && sym->is_defined())
273	    pc->second->insert(pc->second->begin(), *po);
274	  else
275	    pc->second->push_back(*po);
276	}
277    }
278}
279
280// The column where the file name starts in a cross reference table.
281
282static const size_t filecol = 50;
283
284// Print a cross reference table.
285
286void
287Cref_inputs::print_cref(const Symbol_table*, FILE* f) const
288{
289  Cref_table table;
290  this->gather_cref(&this->objects_, &table);
291  for (Archives::const_iterator p = this->archives_.begin();
292       p != this->archives_.end();
293       ++p)
294    this->gather_cref(p->second.objects, &table);
295
296  for (Cref_table::const_iterator pc = table.begin();
297       pc != table.end();
298       ++pc)
299    {
300      // If all the objects are dynamic, skip this symbol.
301      const Symbol* sym = pc->first;
302      const Objects* objects = pc->second;
303      Objects::const_iterator po;
304      for (po = objects->begin(); po != objects->end(); ++po)
305	if (!(*po)->is_dynamic())
306	  break;
307      if (po == objects->end())
308	continue;
309
310      std::string s = sym->demangled_name();
311      if (sym->version() != NULL)
312	{
313	  s += '@';
314	  if (sym->is_default())
315	    s += '@';
316	  s += sym->version();
317	}
318
319      fputs(s.c_str(), f);
320
321      size_t len = s.length();
322
323      for (po = objects->begin(); po != objects->end(); ++po)
324	{
325	  int n = len < filecol ? filecol - len : 1;
326	  fprintf(f, "%*c%s\n", n, ' ', (*po)->name().c_str());
327	  len = 0;
328	}
329    }
330}
331
332// Class Cref.
333
334// Make sure the Cref_inputs object has been created.
335
336void
337Cref::need_inputs()
338{
339  if (this->inputs_ == NULL)
340    this->inputs_ = new Cref_inputs();
341}
342
343// Add an input object file.
344
345void
346Cref::add_object(Object* object)
347{
348  this->need_inputs();
349  this->inputs_->add_object(object);
350}
351
352// Start adding an archive.
353
354void
355Cref::add_archive_start(Archive* archive)
356{
357  this->need_inputs();
358  this->inputs_->add_archive_start(archive);
359}
360
361// Stop adding an archive.
362
363void
364Cref::add_archive_stop(Archive* archive)
365{
366  this->inputs_->add_archive_stop(archive);
367}
368
369// Print symbol counts.
370
371void
372Cref::print_symbol_counts(const Symbol_table* symtab) const
373{
374  if (parameters->options().user_set_print_symbol_counts()
375      && this->inputs_ != NULL)
376    {
377      FILE* f;
378      if (strcmp(parameters->options().print_symbol_counts(), "-") == 0)
379	f = stdout;
380      else
381	{
382	  f = fopen(parameters->options().print_symbol_counts(), "w");
383	  if (f == NULL)
384	    gold_error(_("cannot open symbol count file %s: %s"),
385		       parameters->options().print_symbol_counts(),
386		       strerror(errno));
387	}
388      if (f != NULL)
389	this->inputs_->print_symbol_counts(symtab, f);
390    }
391}
392
393// Print a cross reference table.
394
395void
396Cref::print_cref(const Symbol_table* symtab, FILE* f) const
397{
398  fprintf(f, _("\nCross Reference Table\n\n"));
399  const char* msg = _("Symbol");
400  int len = filecol - strlen(msg);
401  fprintf(f, "%s%*c%s\n", msg, len, ' ', _("File"));
402
403  if (parameters->options().cref() && this->inputs_ != NULL)
404    this->inputs_->print_cref(symtab, f);
405}
406
407} // End namespace gold.
408